1. Field of the Disclosure
This disclosure relates to an apparatus for testing a liquid crystal display (LCD) device, and more particularly to an LCD device test apparatus and method capable of improving test efficiency.
2. Description of the Related Art
The LCD device is a display device that uses light modulation by a liquid crystal cell. The LCD device applies a voltage to the liquid crystal cell and changes its molecular alignment. This converts several optical properties such as birefractivity, light polarization, and light dispersion in the liquid crystal cell into a visual variation.
Such an LCD device can be smaller than a Brown tube (or cathode ray tube). As such, LCD devices are widely applied to office automation appliances such as personal and notebook computer monitors and photocopiers, as well as portable appliances such as mobile phones and pagers.
LCD devices can be classified into various types, including an active matrix type. Active matrix type LCD devices have been actively used in display devices. The process of manufacturing the active matrix type LCD device includes a substrate cleaning process, a substrate patterning process, an alignment film forming process, a substrate combining/liquid crystal injection process, and a mounting process.
More specifically, the substrate cleaning process removes contaminants on lower and upper substrates using a cleanser before and after the substrate patterning process. The substrate patterning process includes a lower substrate patterning process and an upper substrate patterning process.
The upper substrate includes color filters, a common electrode, a black matrix, and other components formed on it. The lower substrate includes signal lines, thin film transistors TFT, and pixel electrodes formed on it. The signal lines include data lines, gate lines, and others. Each of the thin film transistors is formed at an intersection of the gate and data lines. Each of the pixel electrodes is formed on a pixel region defined by means of the data and gate lines. The pixel electrodes are connected to the source electrodes of their respective thin film transistors.
During the alignment film forming process, the lower substrate is first coated with an alignment film and then rubbed. The liquid lower and upper substrates are completed through the substrate combining/liquid crystal injection process. The substrate combining/liquid crystal injection process includes a combining process of the upper and lower substrates, a liquid crystal injection process, an injection hole sealing process, a cleaning process, a grinding process, and a testing process, which are sequentially completed.
The liquid crystal panel as manufactured above can include a stain defect due to errors or carelessness during the above manufacturing process. This stain defect representing divergent brightness can be entirely or partially generated on the liquid crystal panel. Such a stain defect is detected by a macrography (or an examination with the naked eye). In other words, the detection of the stain defect is dependent upon the discernment of an inspector. As such, a poor LCD device with a dot defect, a line defect, and/or a stain defect is often distributed. In addition, it is difficult for an inspector to examine with the naked eye the large-sized LCD device of a recent trend.